Concealed spring anchoring means for trampolines and method of producing same

ABSTRACT

The anchor bars which connect the springs with the flexible bed of a trampoline are attached to the margin of the bed by a series of short tapes which extend perpendicular to the margin and these short tapes are first attached to a second elongated tape which runs parallel with the margins of the bed and thereafter both tapes are secured to the bed so that if one of the short tapes becomes detached from the bed it will still remain attached to the elongated tape and prevent the spring from flying away. The tapes are also positioned to place the ends of the springs and the anchors under the bed and out of possible contact by an acrobat. The side frames of the trampoline frame are also strengthened to support a pad over the outer ends of the springs to prevent injury to an acrobat.

United States Patent 1 1 Sidlinger CONCEALED SPRING ANCHORING MEANS FOR TRAMPOLINES AND METHOD OF PRODUCING SAME [76] Inventor: Bruce C. Sidlinger, 208-214 International Rd., Garland, Tex. 75040 [22] Filed: June 18, 1973 [21] Appl. No.: 370,681

Related US. Application Data [63] Continuation-in-part of Ser. No. 201,376, Nov. 23,

1971, Pat. No. 3,767,009.

52 US. Cl 272/65; 5/187 [51] Int. Cl. A63B 5/18 [58] Field of Search 272/65; 182/139; 5/82,

156] References Cited UNITED STATES PATENTS 1,347,413 7/1920 Schaefer 5/187 1,549,934 8/1925 Vanek et al.. 5/187 1,583,300 5/1926 McTernen 5/187 1 June 24, 1975 2,370,990 3/1945 Nissen 182/139 X FOREIGN PATENTS OR APPLICATIONS 724,244 2/1955 United Kingdom 272/65 Primary E.\-aminerRichard J. Apley Assistant Examiner-Joseph R. Taylor [5 7 ABSTRACT The anchor bars which connect the springs with the flexible bed of a trampoline are attached to the margin of the bed by a series of short tapes which extend perpendicular to the margin and these short tapes are first attached to a second elongated tape which runs parallel with the margins of the bed and thereafter both tapes are secured to the bed so that if one of the short tapes becomes detached from the bed it will still remain attached to the elongated tape and prevent the spring from flying away. The tapes are also positioned to place the ends of the springs and the anchors under the bed and out of possible contact by an acrobat. The side frames of the trampoline frame are also strengthened to support a pad over the outer ends of the springs to prevent injury to an acrobat.

18 Claims, 9 Drawing Figures PATENTEDJUN 24 I975 SHEET FIG. I

PATENTEDJUN24 I975 SHEET CONCEALED SPRING ANCHORING MEANS FOR TRAMPOLINES AND METHOD OF PRODUCING SAME This application is a continuation-in-part of my copending application Ser. No. 201,376, now US. Pat. No. 3,767,009, filed Nov. 23. 1971, entitled TRAMPO- LINE SUPPORT AND CUSHIONING MEANS.

The invention relates to recreational equipment and more particularly to trampolines of the type in which a flexible sheet of material is suspended horizontally by a series of coil springs connected between the margins of the sheet of material and an encircling supporting frame.

In the normal course of use by an acrobat who is not attempting to perform a feat which is beyond the scope of his proficiency, there is little danger of accident so long as the materials of the trampoline have not become worn or deteriorated and so long as the acrobat takes care to land with both feet on the bed.

As a practical matter, there are only two common ways in which a person can be injured by the springs which support the bed. Normally these springs are at least partially covered by a pad, but even when the coils of the springs are not completely covered the usual type of injuries caused by the springs result from a situation in which one end of a spring pulls away from the bed. In that case, a persons leg may become pinched between adjacent turns of a coil when it is released; normally no pinching will take place because the coils remain spread as long as they are hooked up between the frame and the bed. Another possible cause of injuries results when a spring completely pulls away and goes flying into the air, in which case the spectators may also be injured.

The problem of a spring pulling away from a bed is especially acute in the case of outdoor trampolines because the ultraviolet rays of the sun deteriorate the nylon thread usually used to sew the tapes for the spring anchors to the flexible bed which itself is usually composed of woven polypropylene fibers which are much more resistent to the effects of the sun. The problem is accentuated because of the fact that polypropylene thread cannot be used in sewing the tapes to be bed because it does not have the strength of nylon although it is more resistant to the sun. Nylon can be made resistant to ultraviolet rays if it is coated with an appropriate material, but the material used for the coating is soluble in contact with the oil which must be used with the large needles required to sew trampoline beds. The machines which perform this sewing are usually equipped with an oil reservoir into which the needles are continually dipped to keep them lubricated.

Accordingly, it is an object of this invention to provide an arrangement for attaching the spring anchor tapes to the bed in such a way that the effect of the suns rays on the thread is minimized.

Another object of the invention is to attach the spring anchor tapes to the bed indirectly by means of an inter mediate tape which extends along the marginal area of the bed in an arrangement such that if an anchor tape and a portion of the intermediate tape pulls away from the bed the remaining tape attached to the bed absorbs the force and holds the weakened portion for a sufficient time to prevent injury to the acrobat.

Another object of the invention is to minimize the possibility of injuries by arranging the anchor tapes inwardly of the edges of the bed so that the spring anchors and the open ends of the springs connected thereto are covered by the marginal areas of the bed itself.

A further object of the invention is to provide a sturdier support for the resilient pads which are used to cover the trampoline frame and the springs connected thereto.

Other objects and advantages will become apparent from the following detailed description of the invention, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a fragmentary partially broken-away plan view of an improved trampoline according to the pres ent invention;

FIG. 2 is an enlarged elevational view partly in section which is taken on the line 2-2 of FIG. 1 and illustrating a pad which is positioned over the springs which are secured to the frame;

FIG. 3 is a bottom view, facing upwardly, of the showing of FIG. 2;

FIG. 4 is a perspective of one of the pads before it has been placed in position over the springs;

FIG. 5 is a perspective illustrating a clamping member which is used with the pads;

FIG. 6 is a perspective detail view illustrating the manner in which the anchor tapes are stitched to the intermediate tape which is then stitched to the bed;

FIG. 7 is an enlarged fragmentary elevational view illustrating a pad positioned over the springs which are secured to the frame, with the pad in elevated position;

FIG. 8 is a fragmentary perspective of the underside of one end of the pads and illustrating a pair of frameholding brackets which may be used in substitution of or in addition to the pad holding device which is illustrated in FIGS. 4 and 5; and

FIG. 9 is an elevational view of one of the pads with the brackets shown in FIG. 8 after it has been attached to the frame.

In the drawings the numeral 10 indicates a trampoline bed of conventional manufacture which may comprise a rectangular sheet of flexible sheet material, for example, fabric such as heavy cotton or canvas or a closely woven fabric composed of synthetic fibers such as polypropylene, or other substantially non-stretching fibrous material. As is customary, the bed is supported in a horizontal plane by a plurality of resilient members, such as coiled springs 11, spaced at intervals around the margins of the bed and connected at their outer ends to the trampoline frame, indicated generally by numeral 12.

This frame encircles the bed and comprises an inner section formed from heavy metal tubing to form side sections 13 and end sections 14 (only one of which is shown in the drawings) which may consist of a single tube bent to form rounded corners 15, or the frame may be constructed in sections connected to be telescopically fitted together or the sections may be hinged to allow the trampoline to be dismantled for storage or travelling, as is well known in the art.

Along each side there is provided a second metal tubular member 16, spaced outwardly from the tubing 13 and connected to it by cross members 17 at spaced intervals. While the outer member could be extended around the entire periphery of the frame, it is not essential because in the case of an elongated bed the heaviest forces in the springs 11 are exerted generally in the central area of the bed against the side members of the frame.

As disclosed and claimed in my parent application Ser. No. 201,376, the inner members 13 and 14 are provided with rods 18, formed at intervals with loops 19 which can be welded to the frame to space the remainder of the rod away from the frame to provide anchorages for the outer ends of the springs 11 which allows each spring to individually slide along the rod until it finds a position to maintain it at right angles to the margins of the bed. The rod therefore, not only stengthens the frame to some extend but, by allowing for individual positioning of each spring, eliminates a serious safety hazard known to trampoline acrobats as bed dance. Briefly stated, this is a phenomenon which produces in the acrobats mind the illusion that the bed is horizontally unstable.

The inner end of each of the coil springs is connected to a metal anchor rod 20, the respective ends of which are received in the looped ends 21 of pairs of doubled over fabric tapes 22, as is conventional practice. It has also been the practice, in the past, to sew the doubled over ends of these tapes directly to the hem 23 of the bed in such a position that the looped ends 21, as well as the anchors and the spring ends, project outwardly beyond the edges of the bed, as shown in the abovementioned application Ser. No. 201,376.

The present invention differs from that disclosed in said prior application in that the tapes 22 are indirectly secured to the trampoline bed and their locations have been changes so that the anchors 20, with the attached ends of the springs 11, are concealed underneath the marginal area of the bed. Thus, the possibility of injury to an acrobat who lands with one foot beyond the edge of the bed is substantially eliminated.

As can be clearly seen in FIG. 6, the short lengths of tapes 22 are first doubled over at least once to form looped ends 19, after which they are laid transversely upon one face of a second, longer, length of tape 24 with their looped portions in alignment along one side at intervals sufficient to allow pairs of tapes 22 to receive the respective ends of the metal anchors and then the tapes 22 are sewed to the elongated tape 24 by means of one or more rows of stitches 25. The anchors need not necessarily be inserted in the loops at that time, nor do they need to be inserted until the bed is to be connected to the springs.

When this preliminary sewing is completed, the tape 24 is placed on the lower face of the bed 10, adjacent the inwardly turned hem 23 and again one or more rows of stitches 26 are used to secure the tape 24 to the bed. While the hem 23 may be sewed prior to the application of the tape, this need not necessarily be done as a separate operation and, while the stitches used to secure the transverse tapes to the long tape are shown as being spaced apart from the stitches used to apply tape 24 to the bed at uniform distances, this pattern need not necessarily be followed and it should be obvious that no particular pattern stitching need be followed; it could be a zigzag or other irregular pattern. Also, while it is preferable to attach the tape 24 to the bed at a distance inwardly from the edge of the bed to cover the anchors and spring ends, it should be understood that the indirect attachment of the short tapes to the bed contributes an advantage to the invention which is independent of their locations.

The fact that the short tapes are attached to the main tape 24 prior to the latter's attachment to the bed, added to the fact that the assembly of tapes themselves lie on the under surface of the bed, means that whatever securing means, such as the stitching 25, is employed to attach the anchor-holding tapes to the main tape, it will be unaffected either by sunlight or by the ordinary wear and tear produced by the contact of acrobats on the upper surface of the bed. In short, while the stitching 26 which holds the main tape 24 to the bed may deteriorate over a period of time, a failure of this stitching will not result in the immediate release of any of the springs 11. While a portion of the long tape 24 will pull away at the specific point where there is a failure of the stitching 26, the adjacent portions of the long tape will still hold in place and, since the stitching 25 will be completely unaffected by the failure of stitching 26, the separate anchor-holding tapes 22 will not separate from the main tape 24. While, admittedly, the separation of the main tape from the bed at any given point will allow a spring 11 at that point to pull the anchor tapes 22 outwardly from their normal positions there will not be a complete failure of support. This action can be compared to that of a line of mountain climbers connected together by a safety rope; if one slips, he will be prevented from falling more than a few feet by the safety rope.

In the prior application Ser. No. 201,376 an arrangement is disclosed and claimed for holding several elongated resilient safety pads, indicated generally by numeral 27, in place over the frame 12 and springs which utilizes devices which engage with the rods 18 and the tubular frame member only, and such an arrangement is satisfactory for covering the ends of the trampoline although in the drawings the end pad has been omitted.

In the present application a sturdier arrangement is proposed for supporting the pads along the sides of the trampoline, and for this purpose the underside of the pads 27, which may comprise a rigid base such as a sheet of plywood 28, may have an elongated block 29, attached thereto the width of which is such as to loosely fit between the inner and outer members 13 and 16 and whose length is such as to fit between a pair of cross members 17. The thickness of the block should be sufficient to permit the surface 30 of one side to project downwardly at right angles to the base 28 and to abut against the outer periphery of tubular member 13 and for the opposite surface 31 to project angularly and outwardly downward below the horizontal mid plane of tubular member 16 and to abut against this member at a location below this mid plane, as shown in FIG. 2. Such an arrangement will permit the pad to be put in position by placing the surface 31 in contact with the outer tube while the pad is held in a tilted condition, as shown in FIG. 7. The pad is then lowered into the position shown in FIG. 2. Further downward movement, in a clockwise direction, is prevented because the base 28 now rests on tube 13 and angled surface 31 of the block is wedged into contact with the lower portion of tube 16.

As a precaution against accidental lifting of the pad, a metal plate 32, having an elongated central slot 33 can be attached to the underside of the block 29, as by means of a pair of wing nuts 34, secured to bolts 35 which pass through the slot 33 and are anchored in the block. When the wing nuts are loosened, the plate can be slid back, as in FIG. 7, to remove the pad.

Longitudinal movement of the pad along the frame can be prevented by making the block 29 long enough to loosely fit between the cross members 17 or, as shown in FIG. 4, two short blocks can be used, each of which engages at one end with a separate cross member.

An alternate means for securing a pad is shown in FIGS. 8 and 9, wherein a pair of heavy metal brackets 36 are attached by screws 37 to the base 28. One end 38 of each bracket extends downwardly at right angles to abut against frame member 13, while the other end 39 is curved to partially enclose the lower surface of frame member 16. Insertion and removal of the pad is accomplished in the same manner as previously described.

I claim:

1. In a trampoline of the type comprising a flexible bed supported in horizontally stressed taut condition by a plurality of coil springs connected between an encircling metal frame means and the margins of the flexible bed by means of anchors whose respective ends are received in the loops of spaced pairs of tapes attached to the bed adjacent the margins thereof, the improvement which comprises said pairs of tapes being attached to the underside of said bed at locations spaced inwardly of the adjacent margin to position said anchors and the connected ends of the coil springs below the material comprising the bed and also inwardly of said margin, a distance sufficient for the margin of the bed to cover said anchors and the inner ends of said coils springs while exposing the remaining portions of the spring.

2. The invention according to claim 1 wherein said pairs of tapes are sewed to another elongated tape extending parallel with the marginal area of the bed, and said another tape is sewed to said bed.

3. The invention according to claim 2, wherein said pairs of tapes are also sewed to said bed.

4. In a trampoline of the type wherein a flexible bed is supported by an encircling frame by means ofa series of coil spring means connected in stressed condition between a series of short tapes secured at spaced inter vals along the marginal areas of the bed and said frame, the improvement which consists of a plurality of first securing means respectively connecting each of said short tapes only to an elongated second tape extending along a margin of the bed, and second securing means to attach the second tape extending along the marginal area of the trampoline bed on the underside thereof and thereby to cover and protect said first securing means from exposure to forces acting from above said trampoline bed whereby a failure of the second securing means at a given location will not result in the complete loss of spring support at that location.

5. The invention according to claim 4, wherein said second tape is sewed to said second tape and said second tape is sewed to said bed.

6. The invention according to claim 5, wherein said first tapes are comparatively short in length, the first tape being doubled over at least once to form a closed loop at one end, the first tapes being disposed at right angles to the second tape.

7. The invention according to claim 6, wherein said first tapes are also sewed to said bed.

8. The invention according to claim 7, wherein said first tapes are secured between the second tape and said bed.

9. Method of attaching spring anchors to the margin of a trampoline bed comprising the steps of preparing a length of flexible tape to receive a plurality of metal anchors at spaced locations along the length of the tape, and securing said prepared tape to said trampoline bed adjacent a margin thereof.

10. The method according to claim 9 which includes the step of sewing said prepared tape to the bed.

11. The method according to claim 10 in which said preparing step includes the step of sewing a hem in the margin of the bed simultaneously with sewing said prepared tape to the bed.

12. The method according to claim 9 in which said preparing step includes the step of attaching a series of short lengths of doubled over tapes of said first tape at longitudinally spaced intervals thereof.

13. The method according to claim 12 in which said preparing step includes the step of sewing the short lengths of tape to the first tape.

14. The method according to claim 13 in which said preparing step includes the step of sewing the first tape to the bed after the short lengths have been sewed to the first tape.

15. The method according to claim 9 which includes the step of positioning said prepared tape inwardly from the edge of said adjacent margin a distance sufficient to allow the marginal area of the bed to cover said anchors and the ends of springs connected therewith.

16. The method according to claim 15 in which said preparing step includes the step of sewing short lengths of tape to the first tape at longitudinally spaced intervals to receive said anchors.

17. The method according to claim 16 in which said preparing step includes the steps of doubling over the short lengths of tape to form loops for the receipt of said anchors, and sewing said first tape to the bed.

18. The method according to claim 17 in which said preparing step includes the step of arranging pairs of said short lengths of tape to receive the respective ends of substantially straight anchors parallel to the length of the first tape.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. I 3,891,208 DATED June 24, 1975 INVENTOR(S) Bruce C. Sidlinger It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown beiow:

In column 6, lines 21-22, change "in which said preparing step" to -which.

Signed and Scaled this twenty-eight Day Of October 1975 [SEAL] A ttes r.-

RUTH C. MASON C. MARSHALL DANN Arresting 0mm Commissioner of Parents and Trademarks 

1. In a trampoline of the type comprising a flexible bed supported in horizontally stressed taut condition by a plurality of coil springs connected between an encircling metal frame means and the margins of the flexibLe bed by means of anchors whose respective ends are received in the loops of spaced pairs of tapes attached to the bed adjacent the margins thereof, the improvement which comprises said pairs of tapes being attached to the underside of said bed at locations spaced inwardly of the adjacent margin to position said anchors and the connected ends of the coil springs below the material comprising the bed and also inwardly of said margin, a distance sufficient for the margin of the bed to cover said anchors and the inner ends of said coils springs while exposing the remaining portions of the spring.
 2. The invention according to claim 1 wherein said pairs of tapes are sewed to another elongated tape extending parallel with the marginal area of the bed, and said another tape is sewed to said bed.
 3. The invention according to claim 2, wherein said pairs of tapes are also sewed to said bed.
 4. In a trampoline of the type wherein a flexible bed is supported by an encircling frame by means of a series of coil spring means connected in stressed condition between a series of short tapes secured at spaced intervals along the marginal areas of the bed and said frame, the improvement which consists of a plurality of first securing means respectively connecting each of said short tapes only to an elongated second tape extending along a margin of the bed, and second securing means to attach the second tape extending along the marginal area of the trampoline bed on the underside thereof and thereby to cover and protect said first securing means from exposure to forces acting from above said trampoline bed whereby a failure of the second securing means at a given location will not result in the complete loss of spring support at that location.
 5. The invention according to claim 4, wherein said second tape is sewed to said second tape and said second tape is sewed to said bed.
 6. The invention according to claim 5, wherein said first tapes are comparatively short in length, the first tape being doubled over at least once to form a closed loop at one end, the first tapes being disposed at right angles to the second tape.
 7. The invention according to claim 6, wherein said first tapes are also sewed to said bed.
 8. The invention according to claim 7, wherein said first tapes are secured between the second tape and said bed.
 9. Method of attaching spring anchors to the margin of a trampoline bed comprising the steps of preparing a length of flexible tape to receive a plurality of metal anchors at spaced locations along the length of the tape, and securing said prepared tape to said trampoline bed adjacent a margin thereof.
 10. The method according to claim 9 which includes the step of sewing said prepared tape to the bed.
 11. The method according to claim 10 in which said preparing step includes the step of sewing a hem in the margin of the bed simultaneously with sewing said prepared tape to the bed.
 12. The method according to claim 9 in which said preparing step includes the step of attaching a series of short lengths of doubled over tapes of said first tape at longitudinally spaced intervals thereof.
 13. The method according to claim 12 in which said preparing step includes the step of sewing the short lengths of tape to the first tape.
 14. The method according to claim 13 in which said preparing step includes the step of sewing the first tape to the bed after the short lengths have been sewed to the first tape.
 15. The method according to claim 9 which includes the step of positioning said prepared tape inwardly from the edge of said adjacent margin a distance sufficient to allow the marginal area of the bed to cover said anchors and the ends of springs connected therewith.
 16. The method according to claim 15 in which said preparing step includes the step of sewing short lengths of tape to the first tape at longitudinally spaced intervals to receive said anchors.
 17. The method according to claim 16 in which said preparing step includeS the steps of doubling over the short lengths of tape to form loops for the receipt of said anchors, and sewing said first tape to the bed.
 18. The method according to claim 17 in which said preparing step includes the step of arranging pairs of said short lengths of tape to receive the respective ends of substantially straight anchors parallel to the length of the first tape. 